1. Field of the Invention
The present invention relates to system and a device for monitoring a household electric user, in particular a household appliance.
2. Background Information
It is known that household electric users can be classified in two basic groups, i.e. users having sophisticated control systems, capable of a dialog with peripheral and external equipment, and more conventional users developed according to the “stand-alone” philosophy.
A common requisite for both groups of users is to be “user friendly, i.e. allowing their use in a simple and efficient manner, either when installed alone or inserted in a more complex context (such as a home automation system) and allowing both their maintenance and technical servicing in the most efficient way possible.
It is known, for instance, that the components of certain household electric users, such as household appliances, are subject to wear and occasional faults and how repair operations in consequence of such faults are required in the daily practice.
Some household appliances may be equipped with a sophisticated electronic control system, provided with specific sensor means, through which the nature of a malfunction can be identified substantially in real time and appropriately signalled, for making easier its subsequent repair.
On the contrary, in most of the conventional household appliances, the identification of the fault nature of a component by the technical servicing personnel is not immediate; in fact, said personnel is often forced to check several components of the household appliance and/or simulate the performance of a standard work program, in order to identify exactly the instant when such a malfunction occurs, and from this result attempt to go back to the actual origin of the problem.
This may entail several difficulties and a considerable waste of time, which reflect negatively on the costs of repairing.
On the other hand, it is also known that the “preventive” maintenance or servicing activity, being intended as the activity associated to the direct or indirect control of the wear status of some components of a household appliance, is practically non-existent so far. Such an activity, in fact, is nearly exclusively restricted to the advice for the user to let the function or wear status of certain components be checked after a certain period of time elapsed from the installation date of the household appliance, or from a previous maintenance operation.
However, such an approach does not ensure an actual control of the wear status of the components of the household appliance, on account of their real exploitation, nor a prompt detection of initial signs of irregularities in the appliance operation before the latter may turn into a problem for the person using the appliance (hereinafter referred to as “consumer”).
Let us think, for instance, of a household appliance (and in particular, to one of its specific operation programs) being used more frequently with respect to usual standards of use, or vice-versa of a household appliance used only rarely with respect to the standard practice (and without a specific intensive use of a specific program).
It is clear that, in the first case, a certain component of the household appliance will wear out much earlier than the “estimated” date for its replacement, whereas, in the second case, the component may be replaced earlier than necessary during a planned maintenance operation, even if not actually worn.
The present invention is based on the acknowledgement of the fact that it would be highly advantageous for the serviceman called for repair or maintenance operations to avail himself of information relating to the operating status and the “historical” events of a household electric user, above all if the latter is not equipped with a proper sophisticated “self-diagnostic” system for the identification of faults or malfunctions.
Accordingly, the idea at the basis of the present invention is to provide a monitoring device which can be associated in a simple and fast manner to one or more household electric users and which is capable of generating, and eventually receiving, at least information of the diagnostic and statistical type, i.e. information representative, on one hand, of likely malfunctions the electric user is subject to (including those faults not directly detectable by the user) and, on the other hand, of the type of activity performed in the past by the electric user itself.
In this way, through the association of the above monitoring device to a household electric user, the possibility is offered to efficiently identify and/or signal the nature of a malfunction as soon as it occurs, and to detect any initial signs of operation irregularities of the electric user itself, before this may become a problem for the consumer. Similarly, through such a monitoring device it is possible to detect both the conditions and modes of use of the electric user in the time, for allowing a sufficiently exact estimation of the wear status of its internal components.
Other problems concerning the most conventional electric users is that they cannot constitute an active part of a “distributed management” system of the domestic absorption of electric power, i.e. a system realizing the control on the total absorption of power of its elements (electric user) without requiring a central controller, but rather using the capability of each of them to self-adjust their consumption in accordance with the respective priority levels. A system of this type is described for example in EP-A-0 727 668.
Such a mode of management presumes, for its correct operation:                the presence, upstream, of a meter of the total electric power or current absorbed by the household environment, which is capable of spontaneously communicating the measured value to all the electric users connected to a suitable household bus;        the presence of electronically controlled electric users, which are programmed for self-adjusting their own electric power absorption on the basis of the actual available power and in relation to their relevant priorities.        
The managing procedure known from EP-A-0 727 668 has the advantage, with respect to the centralized procedure, of being more powerful and efficient, without requiring any intervention from the consumer.
The increased power lies in that the exploitation of the communication network is reduced (typically less that 5%) and independent from the number of the components of the system, since the network must carry at regular intervals only the information pertaining to the total power being absorbed by the whole set of electric users, onto which each of the same users self-adjusts its absorption; on the contrary, in the systems being based on a central load manager (master), the latter, in order to suitably share the available power among the electric users (slave) requesting power, must continuously interrogate the users by means of an interrogation system of the “polling” type; the polling system, by its nature, tends to keep the band of the communication network highly busy, said engagement increasing in a manner being more than proportional with the increase of the number in the electric users.
The higher efficiency is instead associated with the better exploitation of the electric users, deriving from the fact that their self-adjusting capability (obtained through an appropriate “self-dosing” of the power absorption, being consistent with the actual availability of power of the whole household environment at the moment) allows the simultaneous activation of several appliances without the risk of exceeding the maximum absorption of electric power (contractual power value).
However, the solution described in EP-A-0 727 668 has the drawback of requiring electric users having a sophisticated control system, so that the traditional users, or anyway not programmed for self-adjusting their own power absorption, are unable to contribute in an active and efficient way to the system of distributed management of the household absorption of electric power.
Within this frame, the present invention has also the aim of indicating a monitoring device which can be associated in a simple and fast manner to a generic household electric user, and which is capable of generating at least information of the functional type, i.e. indicating the current operating mode of the electric user itself, to be used for realizing a more efficient management of the electric power absorption.
In this way, through the association of the above monitoring device to a generic household electric user; it is possible to extend also to conventional electric users (or not programmed to that purpose) the advantages being proper of the network connection of the products equipped with sophisticated electronic control systems; all the above for allowing to keep the electric power absorption below a maximum limit in a efficient and clear way for the consumer.